S7-1200/1500 做多个 FBs/FCs 块互连时的影响

块的互连会影响到执行顺序, 因此也会影响到块的接口参数的状态。

S7-1200 和 S7-1500 相互连接的 FCs /FBs 块的执行顺序按照它们的显示顺序执行。本例中的执行顺序是从左到右。

图 1

S7-1200 和 S7-1500 控制器只有当FC / FB 被执行，其布尔量标签的状态才能被获取。在上述示例程序中， 参数 "data".tag8 首先在函数块 “boolCallee1” 输出，然后再在函数块 “boolCallee2” 中被读入。

个人总结:

如果你不想费脑筋去研究各个品牌的差异.上面的程序直接放到2个程序块就好了.

下面的英文就不翻译,免得翻译的不精准,误导别人.

STEP 7 first calculates the networks and and assigns them local tags. Then the block call is compiled with the given parameters.

Description Because of a compiler rule in STL, binary inputs must be specified by FB/FC calls before the calls are executed. Since these can be interconnected with any networks, these networks are calculated first and assigned to local tags. Only then is the called compiled with the given formal parameters. Here the local tags take the place of the binary networks.

In the example below the order is made clear in the implementation in STL.

Fig. 1: Nested FC call with binary inputs

If you call the blocks nested in each other (Fig. 1),

• STEP 7 first compiles the binary networks of the outer call (1).
• In the second step STEP 7 compiles the networks of the inner call.
• Then follows the inner FB/FC call (3).
• Finally there is the outer FB/FC call (4).

This rule also applies if you only place one tag on the binary input as in this example.

Note In this sample program (Fig. 1) the right FB/FC call of "Modul_2" does not use the result of the first FB/FC call as input. Furthermore, we recommend distributing the FB/FC calls over two different networks.